Acting on a whim
by savethetub
Summary: Mephisto acted on a whim at Shiro's funeral. He decided he would no longer watch from the sidelines and decided that he would groom Rin into the exorcist that would kill Satan. How will things change with a Rin that takes his studies seriously? One that started training with his flames earlier? Up for Adoption! PM me if you want to adopt the story.


Rin stood in front of Shiro's grave stone, feeling regret and anger.

He regretted that Shiro wouldn't get to see him grow up and he was incredibly angry that he had been taken away from him.

He looked down at the head stone and let out a long, pent up sigh.

"You shitty old man... Why did you have to die?" Rin muttered to himself, ignoring the tirade of questions in his mind about what would happen next.

That was a first for Rin, he was much more than a live in the moment kind of guy.

'Here, take this. The first number on speed dial is my best friend and he'll probably help you.'

Shiro's words bounced around in his skull as he pulled out the cell phone that Shiro had given him. After a few minutes of debate, he pressed the first number and pressed the phone.

His head snapped up when he heard a phone ringing somewhere in the group, he looked around to find where exactly the phone was but the person answered before he could.

"Ahhh! I was wondering when you would be giving me a ring!~" Said the musical voice on the other end.

Rin continued to look but it wasn't needed because a man in a white overcoat and top hat had poofed in front of him.

Rin looked at the man in confusion then at the phone before he hung up, "Who are you?" He asked in uneasy voice, a little unnerved by the mans sudden appearance. He just had a run in with Satan himself so he was more than a little wary of the unknown.

"My name is Mephisto Pheles! I was a friend of Father fujimoto's." The man explained happily, twirling the patched worked umbrella he carried.

Rin looked around and realized he was completely surrounded, "Are...Are you people exorcist's?" He asked, feeling slightly afraid that they would attack him.

The man smiled at him but it didn't erase Rin's uneasy feeling, if it did any thing it worsened it, "Yes. We are known as the True Cross Order." He explained.

Rin gulped, "...The old man said you's offer me protection." He said, a pleading tone evident. He would never admit it but he was afraid that Satan would try to posses someone else he cared about, he had to leave them to protect them.

Mephisto shrugged apologetically, "I'm afraid that as an honorary knight... I have certain responsibilities. I cannot confuse personal with public interests."

Rin gulped gain, unknowingly adopting a defensive stance.

"You are the son of Satan. you must be killed before you present a threat to humanity." He explained in a careless tone that was beginning to piss Rin off. It sounded like he might as well be a fly to the man!

He grinned slightly at Rin's annoyed expression before continuing, "You have two options. Allow yourself to be killed by us...or... Kill us and flee." He paused then added, "I guess you could also kill yourself, so I guess you really have three options. Now what will it be?"

"Let me join you!" Rin yelled, picking the fourth option. Mephisto's eyes went wide at that as Rin continued, "I don't care what you people say... I am NOT the son of Satan! I refuse to have any relation with that beast!" He yelled defiantly.

He looked over at the grave stone, "My only father...is the old man." He finished in a softer tone.

"And what would you do...if you became an exorcist?" Mephisto asked, the boy had peaked his curiosity.

"KICK SATAN'S ASS!" He responded in a confident tone.

"..."

"..."

"...H...HAHAHAHAHAHAHAHAHAHA!" Mephisto threw his head back in laughter. He was just about to offer his foolish little brother the same option to accomplish the very same goal! He had a feeling that things would be a little more lively with Rin around!

When he stopped laughing, Mephisto made eye contact with a fuming Rin, "I like it!" He said, ignoring everyones pleas for him to reconsider.

Rin looked shocked as well but in a happy way, "Really? You mean it?"

Mephisto grinned at him, "Why of course I do! Although I do have to warn you. The road you have decided to walk on his long and tedious. People will hate you for what you are and some will even try to kill you." He warned, he was testing his little brothers resolve to kill their father.

A determined fire ignited in Rin's eyes as he nodded, "I understand." He said in a mature tone, his voice losing it's playful nature. He would become an exorcist even if it killed him! This was the only way he could think of to honor his father!

Mephisto's eyes widened a fraction as a fire erupted in his little brothers eyes. He had been in Assiah for a very, very, very, very long time and he could count on one hand how many times he's seen determination that strong...and every time he's seen it the world had changed.

He grinned broadly, "I absolutely adore that look!" He said in a sing-song voice, "As a reward I'll even teach you demon's etiquette!" He said, acting on a whim. Rin had peeked his curiosity immensely and he didn't think he could sit on the sidelines like he usually does.

No, He wanted to help mold Rin, nurture his talent with fathers flames and make him the man or demon he was meant to be.

This was one of the rare few times that Mephisto had actually interfered with the core of history directly, sure he had given a push or a nudge here or there but he had never willingly been this involved.

Rin looked puzzled, "Demons etiquette?" He repeated in a confused tone, why would an exorcist know about demon's etiquette?

Mephisto gave his umbrella a twirl, "Yes, demon etiquette. Now, if you would be so kind as to follow me!" he said loudly as he began to walk towards the odd limousine parked in front of the grave yard.

After a moments hesitation, he followed the odd man. If Shiro had trusted this guy, then he should be able too...right?

As Rin got into the oddly colored car he looked back at Yukio who was standing by a group of people. They made eye contact for a moment, Yukio's questioning eyes looking into his guilty blue eyes. After a single moment, Rin broke eye contact and finished getting in the car. He didn't like leaving his little brother in the dark but it was for his own safety. He couldn't be drug into the world of demons and if that meant that Rin could never see him again then thats would happen

Rin slid into the car and awkwardly sat across from Mephisto, who was staring at him with an intense expression.

"Sooo..." Rin said, trying to break the awkward silence between the two. Mephisto "hmmed" loudly as his eyes raked over Rin, "This should be a good start!" He said as he snapped his fingers and the effect was instant.

Rin looked down at the suit he was suddenly wearing in shock, he had already been wearing a suit earlier but it was a cheap wet one. The one he was wearing now looked and felt like it was worth a fortune, "WHAT? HOW?" He yelled in surprise. He looked at his refection on the window and saw that instead of his usual shaggy look, his hair had been sleeked back except for a few small bangs (see manga chapter 38 page 17 for what Rin looks like).

"How did you do this? Can all exorcist do this kind of stuff?" he asked in awe, if so he couldn't wait for this ability! While he didn't enjoy being stuffed into a monkey suit but it was still a neat trick.

Mephisto chuckled in amusement, "No. I'm a special case." He said mysteriously.

Rin's brow furrowed in confusion, "Okkkayyy... But why did you put a better suit on me?"

"Because the current you is competent enough to speak to me." Mephisto replied smoothly.

A tick mark formed on Rin's head, "What? You sure look self-important." He grumbled angrily, he never did well with self entitled snobs.

"Indeed, I am an important person. Eins Zwei Drei." he said than began to speak giberish in Rin's opinion. But moments later he saw that the words weren't giberish, a black veil settled over the interior of the car and Rin suddenly found himself sitting at a table with extravagant foods on it instead of the limousine.

Rin looked around in shock at his new surroundings, trying to figure out what was going on when Mephisto started to speak again, "Since I have been in Assiah..." He trailed off as he gave Rin a questioning look, "You do know what Gehenna and Assiah are right?" he asked, wondering if he would have to explain that to.

Rin nodded, he had spoken to a few of the exorcist at the abby about where Satan had tried to take him and they had given him the run down about the two dimensions. He wasn't sure if he really understood it all but he got the just of it.

Mephisto nodded happily, "Now, as I was saying! Since I have been Assiah for such a long time, I was given lots of names...Loki, Trickster, and Raven too. Mephisto Pheles is a name I've been using for the past two hundred years." He said and laughed out loud at Rin''s shocked and disbelieving look.

Rin was beginning to doubt if anything could ever surprise him at the this point. First he finds out he's the sun of Satan and his father was an exorcist, now he's sitting across from someone immortal guy that was considered a god.

Mephisto smirked playfully before letting loose another bomb, "I am second in Gehenna's hierarchy, the king of time, Samuel. I'm one of the eight demon kings, the royal family of demons and your older brother!" He finished with flourish.

"..."

"..."

"..."

"..."

Rin blinked a few times, not sure if he had heard the man correctly. Did he just say he was a king of hell? And his older brother?

"W-What?" he said dumbly, the information he had just received was taking it's time to sink in.

"You heard me correctly little brother."

"Y-Your a demon too?!" Rin yelled out in surprise, a bit miffed that the exorcist's were going to kill him when their was another son of Satan right in front of them.

Mephisto chuckled, "Yes, it's somewhat of an open secret." He replied, enjoying the shocked look on Rin;s face that seemed to only worsen as each second went by.

"And your my older brother?" He said, feeling slightly sick. This was seriously becoming the worst and weirdest few days of his life.

"Yep, though thats not really important. Theres centuries between us so your more of just some kid to me!~" He said dismissivly.

"Thanks. Now...where are we exactly?"

Mephisto chuckled, "This is Gehenna." He said, seeing if he could make the shocked expression on Rin's face permeant. He can't remember where or when he heard it but someone had told him that if you make a face for to long it would get stuck that way. This seemed like a good time to test that theory.

Rin looked around again in shock, "Damn. I thought there was something fishy about you!" Rin yelled as he jumped up on the table and drew the demon-slaying blade. Rin looked down at the calm looking Mephisto. Rin snarled at him and was annoyed when he didn't get a reaction out of the demon, He had practiced his battle snarl in the mirror and if he didn't say so himself; it was quiet intimidating.

"Calm down. I'm the one who rules time and space. I've only transferred our minds to Gehenna so we couldn't be overheard." He explained and sighed when he saw Rin's eyes narrow in mistrust, "I'm not an enemy. I absolutely adore the human race and their greedy and shameless ways, they provide endless entertainment for me, so I have no wish to end them."

Rin tensed, "Then get me out of here!" He yelled as he jumped towards Mephisto and slammed his blade down where he was sitting. However, the seat was empty.

"I told you, I rule time and space, didn't I?" He said as he gave Rin's tail a savage yank. Rin yelled out in pain, it felt like he had just been struck by lighting! When Mephisto let go, Rin collapsed to the ground. That's when he noticed that he no longer had his sword.

"Etiquette lesson number one! Demon's weaknesses are their tails and their hearts." Mephisto said behind him as he admired Rin's flaming blue sword, "When did you-" He began to demand but was cut off by Mephisto, "I took it from you when I stopped time."

He held up Rin's sword, "Your demon heart is sealed inside this sword." He said, shocking Rin yet again. "Hearts are demons' vital part. Once crushed, we will certainly die...however, it's also our source of power. When it's drawn out like this we can use our true strength but that means our vital part is vulnerable." He got up and approached Rin, who was eying him is suspicion.

"That's why many demons hide their hearts and their tails. This is the demons manner...in other words, etiquette. To be honest I feel rather embarrassed to see you showing them both." He finished as he tossed Rin back his heart.

Rin looked down at the blade with new respect in his eyes, he held his heart in his hands.

Mephisto smirked, "I see you are beginning to understand little brother. Would you care for more lessons?" He asked, smirking playfully.

Rin gave Mephisto a thoughtful look, one he typically didn't use. A large part of him wanted to tell of the king of time and attack him again. That's how he's always settled thing, he would attack first then think later. Yukio was always the thoughtful one, Rin was the impulsive one.

However, the image of Satan possessing father was fresh in his mind, he remembered how Satan had tore up Shiro's body and how Shiro had managed to take control long enough to take his own life. Those images replayed in Rin's head like a broken recored, feeling just as hopeless as he had when Satan had been dragging to the hell gate.

He never wanted to feel that helpless again, he never wanted to see the people he cared about to be hurt because he couldn't protect himself...and the only way he could avoid something like that happing again was if he got stronger. That was exactly what Mephisto was offering him.

"What's the catch?" He asked. Despite being raised in a church, Rin had spent a lot of time on the streets so he knew a deal like this came with a hefty price tag.

Mephisto grinned, glad that Rin wasn't some agreeable fool. He couldn't teach a fool, "Ahh! How world wary! The price is very simple if I don't say so myself! When I put you in cram school, the school for exorcists, you must maintain an A average and dress and act like a respectable young man! In return, I will teach you how to control your flames and I'll even find a teacher to help you with that pesky sword of yours!" He said with flourish.

Rin blinked in surprise, as far as deal went, that was a great bargain on his end. However, there was one concern, "But I don't want to turn into some snob!" He complained, there were few things he hated more than snobs. They were the ones he usually fought because they would either try and bully Yukio or some helpless sap that couldn't defend themselves. The thought of becoming one of them didn't sit well with Rin.

Mephisto rolled his eyes, "You won't become some snob, you'll just be a better version of yourself! I'll teach you all about manners, the things you seem to lack, and make you less of an idiot!"

Rin didn't know if he should thank Mephisto for helping him out or to try and stab him for insulting him. After a few seconds of debate, he chose the former.

"I'll accept your offer...I guess." Rin mumbled, feeling slightly embarrassed for having to receive help. Sometimes it seemed like he would rather drowned than get saved by the life guard, as Shiro use to say.

Slowly the darkness that was Gehenna began to fade and Rin found himself back in the limousine, "I'm glad we could come to an arrangement!" He said, excited at the thought of just how much the boy in front of him would change the world.

**Hope you enjoyed the first chapter! This story is kinda a side project for when I have writers block for my other stories so updates will be sparatic but I'll try to keep it to a bare minuim of once a month, if you want me to continue that is.**

**Please forgive the spelling mistakes, the next chapter will be much better as well as longer. **

**Next chapter will hold Rin meeting the group for the first time and some lesson's on etiquette!**


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